c++ - 如何读取文件

Question

我将 bool 矩阵 (ROW*ROW) 保存到 .txt 文件(0,1 格式)。

如何从文件中读取矩阵？我在下面写了代码，但是我将读取的结果与文件进行比较，数组结果与文件不匹配。谁能告诉我哪里写错了？或者有没有更简单的方法来读取矩阵文件？

bool **results = new bool*[ROW];
    for(int i=0;i<ROW;i++){
        results[i] = new bool[ROW];
    }

    ifstream infile;
    infile.open ("FRM.txt");
    string line;
    int row=0;
    if (infile.is_open())
    {
        while ( infile.good() )
        {
            getline(infile,line);
            istringstream iss(line);
            int col=0;
            while(iss)
            {
                string word;
                iss >> word;
                int number = atoi(word.c_str());
                if(number==1){
                    results[row][col] = true;
                }
                else{
                    results[row][col] = false;
                }
                col++;
            } 
            row++;
        }
    }
    infile.close();

Answer 1

将矩阵表示为嵌套数组通常不是一个好主意。请改用线性数组，并通过宏或内联函数进行索引处理。

我会选择这样的东西:

#include <algorithm>
#include <cmath>
#include <cstdint> // uint8_t requires C++11
#include <iterator>
#include <vector>

// don't use vector<bool>, it creates all sorts of problems
std::vector<uint8_t> results;
{
  std::ifstream infile('FRM.txt', std::ifstream::in);
  if(infile.is_open() && infile.good())
  {
    std::istream_iterator<uint8_t> first(infile), last;
    copy(first, last, std::back_inserter(results));
  }
}

// only if you know the matrix is square! error checking strongly advised!
size_t nrows = size_t(std::sqrt(results.size()));

// accessing element (i,j) is then as easy as
size_t i = 2, j = 3; // assuming nrows > i,j
bool a_ij = results[i*rows+j];